As human beings, we are imperfect and we know it. First of all, when you have bad thoughts, say bad things, and do bad deeds, you lose peace. Then you can get angry, worry, become impatient, feel inadequate, and so on. In sum, you just don't feel good about yourself as a person. Here comes Jesus, and you get to know him and seek and attain union with him. And he completely changes your outlook on life and how you feel about yourself. You are now liberated from sin and feel that the Lord has made you anew. Finally, you are happy in him and about yourself as a person, for you know he loves and treasures you and can make you holy and whole. Alleluia!